1. Field
The described embodiments and invention as claimed relate to oil and natural gas production. More specifically, the embodiments described herein relate to downhole tools systems and methods used to selectively pressurize and test a production string or casing and to selectively activate a tool or a series of tools connected together by flow lines.
2. Description of the Related Art
In completion of oil and gas wells, tubing is often inserted into the well to function as a flow path for treating fluids into the well and for production of hydrocarbons from the well. Such tubing may help preserve casing integrity, optimize production, or serve other purposes. Such tubing may be described or labeled as casing, production tubing, liners, tubulars, or other terms. The term “tubing” as used in this disclosure and the claims is not limited to any particular type, shape, size or installation of tubular goods.
To fulfill these purposes, the tubing must maintain structural integrity against the pressures and pressure cycles it will encounter during its functional life. To test this integrity, operators will install the tubing with a closed “toe”—the end of the tubing furthest from the wellhead—and then subject the tubing to a series of pressure tests. These tests are designed to demonstrate whether the tubing will hold the pressures for which it was designed, to which it will be subjected during operation or an acceptable alternative pressure, depending on the particular circumstances.
One detriment to these pressure tests is the necessity for a closed toe. After pressure testing, the toe must be opened to allow for free flow of fluids through the tubing so that further operations may take place. While formation characteristics, cement, or other factors may still restrict fluid flow, the presence of such factors do not alleviate the desirability or necessity for opening the toe of the tubing. Commonly, the toe is opened by positioning a perforating device in the toe and either explosively or abrasively perforating the tubing to create one or more openings. Perforating, however, requires additional time and equipment that increase the cost of the well. Therefore, there exists a need for an improved method to economically pressure test the tubing and open the toe of the tubing after it is installed and pressure tested.
The present disclosure describes an improved device and method for pressure testing the tubing and opening the toe of tubing installed in a well. The device and method may be readily adapted to other well applications as well. The present disclosure also describes embodiments having degradable or shiftable triggering devise as well as embodiments relating to actuating a series of tools using flow lines that communicate fluid pressure between connected tools for actuation.